大鼠基底前脑Nestin-IR神经元的纤维投射

The Projection of Nestin-ir Neurons in the Basal Forebrain of Adult Rat

目的观察大鼠基底前脑巢蛋白(Nestin)免疫反应阳性神经元的纤维投射。方法采用荧光素逆行追踪技术显示基底前脑投射至海马和额皮质的荧光素标记神经元,结合Nestin免疫组织化学染色,计算荧光素和Nestin双标细胞分别占荧光素标记神经元和Nestin免疫反应阳性(Nestin-IR)神经元的比例。结果荧光素注射至海马后,双标细胞在同侧内侧隔核(MS)、斜角带垂直支(vDB)和斜角带水平支(hDB)占Nestin阳性神经元的比例分别为28.5%、19.6%和18.1%;占荧光素标记神经元的比例分别为25.3%、29%和23.8%,并且,在注射点的对侧也发现有双标细胞存在。荧光素注射至额皮质后,双标细胞在同侧MS、vDB和hDB占Nestin阳性神经元的比例分别为16.6%、8.7%和9.3%;占荧光素标记神经元的比例分别为11.3%、3.5%和5.6%,注射点对侧未发现有双标细胞存在。结论大鼠基底前脑的Nestin-IR神经元发出纤维投射至海马和额皮质,Nestin-IR神经元至海马为双侧投射,而至额皮质为单侧投射。

Objective To explore the projections of Nestin - IR neurons of basal forebrain in adult rat. Methods Retrograde fluorescent tracing method was used to observe the fluorescein labeled neurons projecting from the basal forebrain to the hippocampus and the frontal cortex, combined with nestin immunohistochemistry to determine the fluorescein/nestin double-labeled neurons. The proportion of the double-labeled neurons to the fluorescein labeled neurons and the nestin-IR neurons were calculated respectively. Results After the fluorescein was injected into the hippocampus, double-labeled neurons in medial septum （MS） , vertical limb of diagonal band of Broca （vDB） and horizontal limb of diagonal band of Broca （hDB） of the basal forebrain account for 28.5%, 19.6% and 18.1% of the nestin-IR neurons and for 25.3%, 29% and 23.8% of the fluorescein labeled neurons on tbe same side of the injection site. Moreover, double-labeled neurons were also observed on MS, vDB and hDB of the opposite side of the injection site. After the fluorescein was injected into the frontal cortex, double-labeled neurons in MS, vDB and hDB of the basal forebrain account for 16.6%, 8.7% and 9.3% of the nestin-IR neurons and for 11.3% , 3. 5% and 5.6% of the fluorescein labeled neurons on the same side of the injection site. No double-labeled neuron was found on tbe opposite of the injection site. Conclusions Nestin-IR neurons in the basal forebrain of adult rat give off fibers projecting to the hippocampus and the frontal cortex. In addition, the projections of the Nestin-IR neurons to the hippocampus are double-sided and to the frontal cortex are single-sided.